Read the name of a variable, and the value for it, in the echo area
and then set the variable to that value. Completion is available when
reading the variable name (see The Echo Area); completion is also
available when reading the value when that makes sense.

M-x describe-variable

Read the name of a variable in the echo area and display its value and
a brief description.

Here is a list of the variables that you can set in Info.

automatic-footnotes

When set to On, footnotes appear and disappear automatically;
else, they appear at the bottom of the node text. This variable is
Off by default. When a node is selected, a window containing
the footnotes which appear in that node is created, and the footnotes
are displayed within the new window. The window that Info creates to
contain the footnotes is called *Footnotes*. If a node is
selected which contains no footnotes, and a *Footnotes* window
is on the screen, the *Footnotes* window is deleted. Footnote
windows created in this fashion are not automatically tiled so that
they can use as little of the display as is possible.

automatic-tiling

When set to On, creating or deleting a window resizes other
windows. This variable is Off by default. Normally, typing
‘C-x 2’ divides the current window into two equal parts. When
automatic-tiling is set to On, all of the windows are
resized automatically, keeping an equal number of lines visible in
each window. Any *Completions* and *Footnotes* windows
are exceptions to the automatic tiling; they retain their original
size.

cursor-movement-scrolls

By default, cursor movement commands stop when top or bottom of a node
is reached (see Cursor Commands). When this variable is set to
On, cursor movement commands become scrolling and their
behavior is controlled by the scroll-behavior variable (see
below).

errors-ring-bell

When set to On (the default), errors cause the bell to ring.

gc-compressed-files

When set to On, Info garbage collects files which had to be
uncompressed. The default value of this variable is Off.
Whenever a node is visited in Info, the Info file containing that node
is read into memory, and Info reads information about the tags and
nodes contained in that file. Once the tags information is read by
Info, it is never forgotten. However, the actual text of the nodes
does not need to be retained unless a particular Info window needs it.
For non-compressed files, node text is not remembered when it is no
longer in use. But de-compressing a file can be a time-consuming
operation, and so Info tries hard not to do it twice. This variable
tells Info it is okay to garbage collect the text of the nodes of a
file which was compressed on disk.

ISO-Latin

When set to On, Info accepts and displays ISO Latin characters;
the default is Off, i.e., an ASCII character set.
ISO-Latin tells Info that it is running in an environment where
the European standard character set is in use, and allows you to input
such characters to Info, as well as display them.

min-search-length

Minimum length of a search string (default 1). Attempts to initiate a
search for a string (or regular expression) shorter than this value,
result in an error.

scroll-behavior

scroll-behaviour

Control what happens when forward scrolling is requested at the end of
a node, or when backward scrolling is requested at the beginning of a
node. The two variable names are synonyms. The default value for
this variable is Continuous. Possible values:

Continuous

Try to get the first item in this node’s menu, or failing that, the
‘Next’ node, or failing that, the ‘Next’ of the ‘Up’
node. This behavior is identical to using the ‘]’
(global-next-node) and ‘[’ (global-prev-node)
commands.

Next Only

Only try to get the ‘Next’ node.

Page Only

Just stop, changing nothing. With this value, no scrolling command
can change the node that is being viewed.

This variable normally affects only scrolling commands.
See cursor-movement-scrolls, for information on how to widen its
scope to cursor movement commands.

scroll-last-node

Control what happens when a scrolling command is issued at the end of
the last node. Possible values are:

Stop

Do not scroll. Display the ‘No more nodes within this document.’
message. This is the default.

Scroll

Scroll as usual. Since the last node is usually an index, this means
that the very first node from the menu will be selected.

Top

Go to the top node of this document.

This variable is in effect only if scroll-behaviour is set to
Continuous.

Notice that the default behavior has changed in version 4.12. Previous
versions behaved as if scroll-last-node=Scroll was set. This
behavior was counter-intuitive, therefore since version 4.12 the
default is to stop at the last node.

scroll-step

The number of lines to scroll when the cursor moves out of the window.
Scrolling happens automatically if the cursor has moved out of the
visible portion of the node text when it is time to display. Usually
the scrolling is done so as to put the cursor on the center line of the
current window. However, if the variable scroll-step has a
nonzero value, Info attempts to scroll the node text by that many lines;
if that is enough to bring the cursor back into the window, that is what
is done. The default value of this variable is 0, thus placing the
cursor (and the text it is attached to) in the center of the window.
Setting this variable to 1 causes a kind of “smooth scrolling” which
some people prefer.

search-skip-screen

Set the starting point of repeated searches (see repeated-search).
When set to Off (the default), repeated searches start at the
position immediately following (when searching in forward direction),
or immediately preceding (when searching backwards) the cursor. When
set to On, repeated searches omit lines visibly displayed on
the screen. In other words, forward searches (}) start at the
beginning of the next page, and backward searches ({) start at
the end of the previous page.

show-index-match

When set to On (the default), the portion of the matched search
string that you typed is indicated (by displaying it in the
“opposite” case) in the result message (see next-index-match).

visible-bell

When set to On, Info attempts to flash the screen instead of
ringing the bell. This variable is Off by default. If the
terminal does not allow flashing, this variable has no effect. (But
you can still make Info perform quietly by setting the
errors-ring-bell variable to Off; or using an external
command to mute the bell, e.g., xset b 0 0 0.)